Product development can't be achieved with a one unique specialty. Prototyping means getting your hands dirty.
Good design is obvious, anything else is obtrusive
I believe that in order to design a true product to be used by humans, you have to observe humans and listen to them. Ask questions and be patient, understand their point of view. Never underestimate their feedback. It'll get you far.
Every obstacle is a tiny frustration. You'll get nowhere without them. If you don't step back and take a breath, you'll never succeed.
Product design is best conquered in a team, every remark is constructive. Do what you're good at most of the time, and what you're not the least of it, until you master it.
The best projects we've had were the most challenging to commence.
To sum it up, a strong set of skills is needed, an appetite for learning, experimenting with materials, some obvious, some unique. "Learn as you go", is one moto I'd agree with. We have all of the above. Inquiries are free :)